Pneumatic tire casing



March 27, 1951 J. w. GRIFFITH 2,546,858

PNEUMATIC TIRE CASING Filed Oct. 20, 1948 impregnated Fub ric INVENTOR. ea. J ohn W.Griffith.

Patented Mar. 27, 1951 UNITED stares "it-:ATENT omu ca' PNEUMATIC TIRE=5GASING John \VJGriifith, Pittsburghla. Applicationfictosber/20, 1948', Seria1 No'.5'5;530Ii '7"Claims.. 1-.

This inventionrrelatesa to; pneumatic tire. 085$. ings and; in; particular, to; reinforced pneumatic 1 tire'casingszhavingpuncturearesistingichamcteit isticcz.

Thetusetoffmetallicrreinforcements:in tiresahas. been-.suggested before;. In s-uch cases the metallic inserts such as wire, cable andt the-like'rhavei been: employed iprimarily to reinforce the: casing opposed: toy= rendering the: the substantially. puncture proof;v

An. object of.- this invention to: provide. a pneumatic tire casing having; substantially; continuous; sheath of metal; embedded therein in: predetermined zrelation with respect-to; the-tread and side wall portions;to:impart-.thereto subrstantially puncture:prootcharacteristicm Another; object: of: this; invention is; the pro-- vision:- in: a. pneumatic; tire casing ofr a substane tiall-y continuous .resilientlmetallic sheathiori'neeinforcing the casing; and. imparting. puncture: proof! characteristics: thereto;

A further object-5 of I this: invention; is; the; pro"- vi'siorr of; a: pneumatic:- tire casing: having; a pluzrality; of spaced resilient: sheathsa-of: metal em:--

bedded thereintorender theetreadiand-partsof: o

the side wall portions thereof substantiallypuncture proof;

Otherzobjectse of this invention will ;become. apparent: from; the: following. description; when. taken in: conjunction. with" the accompanying drawing, in'whichr E gure lis a viewin vertical sectionof. arpneue maticztirecasing. embodying therteachingsaof this? invention;

Ei'gureez'is anwexaggerated view-"inzsec-tionxzof.v a: portionz-of" the casing takenalongthe line zII-IT: ofrFigureel:

'Figure Bi's a view-in:verticahsectiOn-of a; nneu matie tirei casing"illustrating another emlo'odi ment" of this invention;

l igurwl is' ail-exaggerated viewinsectionpf a portiorrof the-casing'taken along the line IV -IV of Figure: 3;

Figure 5 is a plan view of a resilient sheath; the wires thereof beingq greatly exaggerated in thickness, to, be. utilized. in. the. embodiments. of Figures, 1'-i and. 3, and

I Figuresfifiis -a fragmentary planmiewoflanother. embodiment of: the. sheathutilizediinithezcasi-ngs of; this? invention.

Referring ato .F?ig ure;1', thereis-illustrated a tire casing; I; having a tread portion: I 2. sid'ee wall portionsel {la-and ahead zportionssl 6%.- The. outerrsurw face' aor 'portion,ofithacasing: Hllis ofirubben as" in;

I52-.-19.8). 2 usual practice-ianclgthezbeadipontions t l are: IIIDT-F vided with: theusual bead wires or: cablessl 8i In';.this:embodiment:. theinternala portionioiithe'i casing;- l ,9 ia-formed of layers 2.0of: fab ric;-;suchass canvas orv duck, impregnated with: rubber. Which;- extend; around the-a casing. and; are? wrappedi around-the beadwires. l B=- and?threealayersifi; 2.4? and 2 Biol. wire zaidispcsed tin predetermined arelae tionwith I respectto the-layers 2 ll-and;thes.-tread and zside wall 1 portions:.

Asrshown in Figures 5 (and .6 .eachof the-layers: 22, 24 and ZlhcomprisesapluralitypfindividuaL wires: 28. disposed closely adj acent and in side: by sidezrelationito one-anotherinisubstantially pane" allel planesw-hich extend-radiallmfrom :azcommorr pointt whereby when assembled. in; the casing r l 0; the wires-.28;extendi'throughout the tread 1301'!"- tion i2-.anda part ofthe side wallportions M;v AsiillustratediiniEigui e 5. i although; greatly.- e aggeratedtherein; theiendseof the .adjacentwirese 28 are in substantial contact engagement WhilGr" the: centralportions of; thewires.-..- are slightly spaced-by reason of the radial .-;positioningof the;- wires to form: a; circular, member, the {cross sec.

- tion of-. which is. of]; substantially: the: cross. sees-- tional' shape of. the treadandpart of; thewsidef. walls. of. the carcass of.- the; casing:v

The wires .28 are preferably? of. resilient hard drawn ispri ng steel-iwithi a': thinicoating of. copper}:

, (not iillus-trated). thereon and have.=a-.gauges-or. I diameter of: .037. inch and:- at tensile -strength of not-.lessthan 2.00.,O0.0 -poundsvperisquarezinchr. re-ferrecl.- to; hereinbefore; the." adjacent. wires 28; heina insubstantially: parallel; planesradially:- disposedhave fine interstices. or spacings; 30 therebetween, such interstices. being greatly; eX- aggeratedwin theedrawingn Preferablv the inter-'- stices 30 are infinitesimal,..being:of the order/on 0. 001,- toa0.005 inchiwrhereby: thea assembled-wires 40; 28= formina-eachzofithealayers=2 2 2.4 and-. 26 comeprise isubstantiallv continuous.- sheaths-of: install In'order tomaintain theindividualj-Ewiressfl in assembled relation relative to: one another; .a: pain of Wires 32-- (shown .inFigure l) of. predeter- 4 mined circular shape-and size ito seat againstthe.

shape to correspond to the curvature which is to be normally maintained in the casing ID as shown in Figure 1.

Instead of maintaining the wires 28 in assembled relation as by means of the pair of wires 32, the ends of the adjacent wires 28 may be secured together as shown in Fig. 6 by means of small beads 36 of solder or tack weld metal at each of the opposite ends of the individual wires. In practice, uniform beads 34 can be readily formed whereby the resulting layer or sheath will have proper balance. 7

As illustrated in Figure 1, the individual wires 28 of the layers 22, 24 and 28 are of different length whereby when assembled alternately with the layers 20 of impregnated fabric, the layers 22, 24 and 26 extend across the tread portion [2 and part of the side wall portions 84, terminating in the opposite side walls in stepped relation with the number of layers of wire 28 progressively diminishing in the direction towards the bead portions 15. The layers Zllof fabric and layers 22, 24 and 25 of wire'may be assembledby s'upen imposing the layers in their alternate relation upon a suitable mold form or core and either partially vulcanizing the assembled layers and thereafter assembling the partially vulcanized assembly in a suitable mold with the rubber forming the outer portion or surface of the casing l and then completing the vulcanization, or the assembled layers and rubber may be vulcanized into an integral unit in one step.

Upon examination, it is found that the rubber of the layers 29 and of the outer portion or surface of the casing H3 penetrates and fills the infinitesimal spaces 30 between the adjacent wires 28 of the layers 22, 2d and 26 and is securely bonded to the copper coated surface of the wires 28. The flash of copper on the steel wire facilitates the bonding of the rubber to the wire.

In the embodiment illustrated in Figs. 3 and 4, only one layer 29 of fabric impregnated with rubber is employed to form the internal surface of the casing Hi. In this instance the layers 22, 24 and 26 of wire are spaced b suitable layers of rubber therebetween, the layers of wire providing the strengthening factor as well as imparting puncture proof characteristics to the casing l0.

, As in the embodiment of Figs. 1 and 2, the layers 22, 24and 25 terminate in the opposite side wall portions I4 in stepped relation and progressively diminish towards the bead portions l6 whereby the layers of wire are independent of the bead portions 6. The rubber is securely bonded to the individual copper coated wires 28 forming the layers 22, 2 3 and 26 and fills the infinitesimal openings between the wires. 7

' In both embodiments, the layers 22, 24 and 26 of wire form spaced resilient sheaths of substantially continuous metal across the tread portion l2 and parts of the side Wall port-ions 14. Since the interstices 30 between the adjacent wires 28 of each layer are infinitesimal, it will be appreciated that it will be extremely difdcult for a hall or the like to penetrate through the casing Ill, especially through the tread portion 12 or the parts' of the side'wall'portions i6 adjacent the tread portion which in practice are most commonly punctured and which in the case of the tirecasing of this invention are protected by the embedded spaced layers of wire. This is especially trueif the layers 22, 24 and 26 are so positioned that the spaces 35 of the outermost layer'is aligned with the wires 28 of the next layer so that in effect the infinitesimal spaces of adjacent layers of wire are staggered.

Since the wires 23 and consequently the resulting layers or sheaths formed therefrom are resilient, the presence of the spaced sheaths in the casing does not detract from the resiliency of the casing. Further, the wires 28 aid in the dissipation of heat developed in the tread of the tire during use whereby the life of the rubber in the casing is lengthened. v v

' Although the embodiments illustrated in Figures 1 and 3 utilize three of the spaced layers of wire, itis to be understood that such number may be increased depending upon the size of the tire. In all cases, however, the metallic sheaths should terminate in stepped relation in the opposite side walls as described in order that the resultin casing will not be too stiff adjacent the bead portions and also to maintain the weight of the tire at a minimum. Whether the tire casing embodies a number of layers of the fabric or only one will depend upon design considera' tions of the strength or stifiness'required of the side walls adjacent the bead portions and not upon the strength considerations in the tread portion a the layers of wire provide adequate strength therein.

The tire casing of this invention is substantially puncture proof, a characteristic desired in tires for years. Such characteristic is obtained without detracting from the general resiliency of the casing or greatly adding to the cost thereof. Further, the casing is constructed of standard components and can be readily reproduced.

I claim as my invention:

1. A pneumatic tire casing comprising, in combination, a rubber carcass having tread, sidewall and bead portions, a plurality of layers'of wire disposed in the carcass in spaced relation to each other, each of the layersof wire comprisin a plurality of individual wires disposed adjacent to one another radially extending in substantially parallel planes with the opposite ends of each of the wires terminatin in the opposite side walls of the carcass thereby forming a sheath of metal extending about the carcass in' embedded relation therein, and means securing the adjacent ends of said individual wires one to another for maintaining the wires in said substantially parallel planes within the carcass.

2. A pneumatic tire casing comprising, in combination, a rubber carcass having tread, sidewall and bead portions, a plurality of layers of re silient wire disposed in the carcass in spaced relation to each other, each of the layers of wire comprising a plurality of individual wires'disposed adjacent to one another in radially extending substantially parallel planes with the opposite ends of each of the wires terminating in the opposite side Walls of'the carcass thereby forming a resilient sheath of metal extending about the tread portion in embedded relation therein, and means securing the adjacent ends of said individual wires one to another for maintaining the adjacent wires in said substantially parallel planes wthin the carcass.

3. A pneumatic tire casing comprising, in com: bination, a rubber carcass having tread, sidewall and bead'portions, a plurality of layers of wire disposed in the carcass in spaced relation to each other, each of the layers of wire compris ing a plurality of individual wires disposed adjacent'to' one another in radiallyextending substantially parallel planes with the opposite ends of each of the wires terminating in the opposite side walls of the carcass thereby forming a sheath of metal extending about the carcass in embedded relation therein, and means securing the adjacent ends of said individual wires one to another for maintaining the wires in said substantially parallel planes within the carcass, said spaced layers havin the ends of the wires forming the sheaths terminating in the side wall portions in spaced stepped relation whereby the tread portion and a part of the side wall portions embody a plurality of the spaced sheaths with the number of sheaths progressively decreasing in the side wall portions toward the bead portions.

4. A pneumatic tire casing comprising, in combination, a rubber carcass having tread, sidewall and bead portions, a plurality of layers of re silient wire disposed in the carcass in spaced relation to each other, each of the layers of wire comprising a plurality of individual wires disposed adjacent to one another in radially extending substantially parall l planes with the opposite ends or" each of the wires terminating in the opposite side wall portions of the carcass thereby forming a resilient sheath of metal extending about the carcass in embedded relation therein, means securing the adjacent ends of said wires one to another for maintaining the wires in said substantially parallel planes, the

adjacent wires in the tread portion having fine u interstices therebetween filled with the rubber of the carcass whereby the rubber envelops the Wires, said rubber being bonded to said wires.

5. A pneumatic tire casing comprising, in combination, a rubber carcass having tread, sidewall and bead portions, a plurality of layers of resilient wire disposed in the carcass in spaced relation to each other, each of the layers of wire comprising a plurality of individual wires disposed adjacent to one another in radially extending substantially parallel planes with the opposite ends of each of the wires terminating in the opposite side wall portions of the carcass thereby forming a substantially continuous resilient sheath of metal extending about the carcass in embedded relation therein, means securing the adjacent ends of said wires together for maintaining the wires in said parallel planes,

the spaced layers having the ends of the wires forming the sheaths terminating in the side wall portions in spaced stepped relation whereby the tread portion and a part of the side wall portionsinclude a plurality of the spaced sheaths with the number of the sheaths progressively decreasing in the side Wall portions toward the bead portions.

6. A pneumatic tire casing comprising, in combination, a rubber carcass having tread, sidewall and bead portions, the rubber carcass including a plurality of alternate layers of rubber and layers of resilient wire, each of the layers of wire comprising a plurality of individual wires disposed adjacent to one another in radially extendin substantially parallel planes With the opposite ends of each of the wires terminating in the opposite side wall portions of the carcass thereby forming a substantially continuous resilient sheath of metal extending through the tread and part of the side Wall portions of the carcass in embedded relation therein, means securing the adjacent ends of said wires together for maintaining the wires in said substantially parallel planes, the spaced layers of wire having the ends thereof terminating in the side wall portions in spaced stepped relation independent of the bead portions, the alternate layers of rubber and layers of resilient wire being bonded together into an integral unit.

7. A pneumatic tire casing comprising, in combination, a rubber carcass having tread, sidewall and bead portions, the rubber carcass including a plurality of alternate layers of fabric impregnated with rubber and layers of resilient wire, each of the layers of wire comprising a plurality of individual wires disposed adjacent to one another in radially extending substantially parallel planes with the opposite ends of each of the wires terminating in the opposite side wall portions thereby forming a substantially continuous resilient sheath of metal extending through the tread and part of the side wall portions of the carcass, means securing the adjacent ends of said Wires together for maintainin the wires in said substantially parallel planes, the spaced layers of wire having the ends thereof terminating in the side wall portions in spaced stepped relation with the layers of Wire progressively decreasing in the direction of the bead portions, the rubber of the fabric layers bonding the adjacent layers of wire therebetween.

JOHN W. GRIFFITH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 941,871 Gautlier Nov. 30, 1909 952,072 English et al Mar. 15, 1910 961,443 Herman June 14, 1910 1,288,960 Mix Dec. 24, 1918 

